1. Technical Field
The invention relates to a resource management system, printer, network card and program, and method. In particular, the invention relates to a resource management system, a printer, a printer network card and a resource management program, and a resource management method that preferably reduces the likelihood of a software operation becoming instable and thereby can suppress resource usage from increasing.
2. Related Art
So far, as a technology that manages resources such as hardware, for instance, a resource management system described in JP-A No. 2004-94782 and an image formation unit described in JP-A No. 2003-330732 are known.
The invention disclosed in JP-A No. 2004-94782 is constituted by including a limit setter that sets a range operable to a resource that is utilized when software is executed on an information device; and an operation range verifier that verifies that the software is operated within an operable range set by the limit setter. The operation range verifier, when demanded from the software to use the resource, compares an operable range that is set and a volume of the demanded resource, and, when it is outside of the operable range, the software is stopped from executing.
In the invention described in JP-A No. 2003-330732, an image formation device that has a first execution environment and a second execution environment, is constituted by including a resource management portion that manages resources such as memories that the second execution environment uses. The resource management portion limits resources that the second execution environment can use.
An execution environment of a JAVA (registered trade mark) application is made of three execution environments where an application called JVM (Java (registered trade mark) Virtual Machine) is executed on an OS (Operating System) and a JAVA (registered trade mark) class set made of a plurality of JAVA (registered trade mark) classes is executed on the JVM.
FIGS. 18A and 18B are diagrams describing an execution environment of the JAVA (registered trade mark) application.
When the inventions described in JP-A Nos. 2004-94782 and 2003-330732 are applied to such an environment, as shown in FIG. 18A, a volume of the OS resource that the JVM uses can be limited.
On the JVM, in some cases, a plurality of JAVA (registered trade mark) class sets is executed in parallel. In this case, although a volume of the resource that the JVM uses can be limited, on the JVM, the JAVA (registered trade mark) class set can freely use the resource in the limited range thereof. Accordingly, when a certain JAVA (registered trade mark) class set uses the resource close to an operable upper limit value, other JAVA (registered trade mark) class sets cannot be executed, resulting in a problem in that an operation becomes instable.
The JAVA (registered trade mark) class set, necessitating the JVM in execution thereof, is not able to execute directly on the OS. Accordingly, when the inventions of JP-A Nos. 2004-94782 and 2003-330732 are applied to try to limit a volume of the resource that the respective JAVA (registered trade mark) class sets use, as shown in FIG. 18B, there is no way other than executing the JVM respectively for one JAVA (registered trade mark) class set. However, according to such an execution method, with an increase in the JAVA (registered trade mark) class sets, the JVMs increase as well. That is, a volume of resources used as a whole increases to be impractical.
Furthermore, other than a volume that the JAVA (registered trade mark) class set itself uses, when a volume of a resource that the JVM uses to execute the JAVA (registered trade mark) class set is also large, a problem similar to the above is caused. For instance, in a JAVA (registered trade mark) class set where many instances are simultaneously generated for instance, the JVM uses a large volume of resources to generate instances.